Why Does Kidney Function Matter And What Is The Risk Of The Contrast Material Causing Kidney Damage
For both MRI and CT contrast agents, once injected they are cleared from your body by your kidneys. If your kidney function is below normal then two things happen. First, the contrast agents are cleared more slowly from your body. If kidney function is very poor this prolonged exposure can lead to a change in the injected MRI agents chemical composition and create a small risk of developing NSF. For MRI contrast agents there is no risk of developing the skin disease of concern if the eGFR is > 30. For CT contrast materials, where a larger volume of the contrast agent is used than for MRI, the functioning kidney is exposed to contrast material for a longer time than in people who have completely normal kidneys and can clear it more rapidly. This prolonged exposure is thought to increase the risk of developing kidney damage. The risk is very low, about 1% unless the patients eGFR is < 30, then the risk goes up slightly. Even when kidney damage occurs, it is almost always temporary and will resolve without treatment.
Is It All A Myth
Over the past decade, a number of large epidemiologic studies suggested that acute kidney injury following exposure to iodinated contrast media is not necessarily caused by the contrast media. Some reports even questioned whether it is a real disease. This has sparked much debate and led to newer names for the phenomenon, including postcontrast acute kidney injury and contrast-associated acute kidney injury . The rationale of these new definitions is to eliminate the causality associated with the term CI-AKI.
Nomenclature and definitions of kidney injury related to iodinated contrast media
Whether one believes CI-AKI is real or a myth, this debate is not merely theoretical because conclusions drawn have significant implications for the care of our patients who have chronic kidney disease. For example, Chertow et al reported an inappropriately low rate of cardiac angiographic procedures in patients who have chronic kidney disease. Presumably, procedures were withheld out of concern for CI-AKI. They coined the term renalism to indicate the perhaps inappropriate attention to the kidneys while ignoring the bigger picture. Although it is not yet reported, one could presume the notion of avoidance may encompass all contrast-enhanced CT studies in the chronic kidney disease population.
Therefore, despite the lack of conclusive data, CI-AKI remains very much a real entity, although the incidence is lower than originally thought.
Why Do I Need Contrast Medium
X-ray or radiography is the imaging of body structures using X-ray beams that are absorbed by different parts of the body in different ways to create an image or picture. This includes CT scans and plain radiography/X-rays. Different structures or parts of the body look lighter or darker on the images, depending on what these structures are made of for example, soft tissue shows as dark grey and bone as light grey. This difference in how various structures of the body absorb the X-ray beam and produce an image is called contrast.
MRI and ultrasound do not use radiation, but still produce images showing the different parts of the body. MRI uses a magnetic field, and ultrasound scans use high-frequency sound waves.
The use of contrast media highlights the differences between various parts of the body, including those parts that have a similar composition. This provides a clearer image of how the body is working, or if there is any disease or abnormality present.
With clearer images, the radiologist can provide your doctor with a more accurate diagnosis of the symptom or condition, to assist in deciding what treatment will be most appropriate.
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Children On Contrast Dye
Most of the time, doctors will require a sedative for children who will undergo an imaging test.
This is to make sure your kid wont be moving as much as they tend to be more frantic or agitated during these types of medical procedures.
If your child has no health complications, they will normally excrete the contrast dye within a day or so.
A Cautionary Note On The Use Of The Present Guideline
The revised guideline has been prepared for use according to the National Health Insurance regulations in Japan. The revised guideline provides direction on using contrast media in the clinical setting. Physicians have the final responsibility to maximize the benefits for their patients by deciding, on the basis of their patients physical and pathological conditions, whether contrast media should be administered and whether measures to prevent CIN are necessary. Any use of contrast media that is not consistent with the revised guideline reflects the decisions made by the attending physicians on the basis of conditions specific to their patients, and their decisions should be prioritized. The present guideline does not provide any legal basis for prosecuting physicians who do not use contrast media according to the guideline.
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Where Can I Find Information About Iodine And Gadolinium Contrast Media
This information sheet deals with the use of iodine and gadolinium in patients whose kidney function is much less than normal. If you have kidney disease or diabetes, you will need to have a recent kidney function test result before contrast is given, unless the test or procedure is an emergency. If you are unsure whether your kidneys are working normally or you have other medical conditions, then you should contact your referring doctor to see if a kidney blood test is required before the imaging examination.
The radiologist needs to know how your kidneys are functioning before giving contrast. Both gadolinium contrast and iodinated contrast leave the body in the urine, which is made by your kidneys.
The InsideRadiology website contains further separate information on both iodine and gadolinium . These information items include details of the risks and benefits involved for those with reduced kidney function and normal kidney function. The items also include information about other side effects when using contrast media.
Contrast media are regarded as generally very safe for patients who do not have severe kidney disease. If you do have severe kidney disease, the radiologist in discussion with your doctor might still decide that you should have contrast, because the benefit of the test or procedure outweighs the risk.
What Are The Side Effects Of Ct Scan Dye
Other reactions to the procedure might be broadly considered side effects of CT scans. A common reaction to IV administration of an iodine-based contrast dye is an abrupt systemic flushing that is also described as a feeling of heat spreading throughout the body.
Is contrast dye safe?
While patients are told that the contrast dye is safe and leaves the body within a few days if you have normal kidney function, mounting evidence suggests that is not the case and gadolinium may be retained, posing serious health risks.
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What Lab Values Indicate A Need For Concern When Contrast Material Is Injected
Historically serum creatinine was the lab value used to assess kidney function. A better and more accurate measure is a lab result called estimated glomerular filtration rate . eGFR takes into account the serum creatinine value and also patient age, race and gender which affect kidney function results. At UCSF we use this very accurate blood test to assess kidney function and it can be obtained quickly, right before a scan. For CT, eGFR > 45 indicates no increased risk of kidney damage from contrast material. eGFR > 30, but less than 45 indicates that while it is safe to get contrast material, there is a small risk of causing kidney damage. In that situation, we will inject additional fluid into the patients vein before and after the contrast material injection. This hydration is effective to prevent any renal damage. For MRI, it is safe to give a regular dose of contrast material as long as the patients eGFR is > 30.
What Is A Ct Scan Of The Kidney
Computed tomography is a noninvasive diagnosticimaging procedure that uses a combination ofX-raysand computer technology to produce horizontal, or axial, images of the body. A CT scan shows detailed images of any part ofthe body, including the bones, muscles, fat, and organs. CT scans are moredetailed than standard X-rays.
In standard X-rays, a beam of energy is aimed at the body part beingstudied. A plate behind the body part captures the variations of the energybeam after it passes through skin, bone, muscle, and other tissue. Whilemuch information can be obtained from a standard X-ray, a lot of detailabout internal organs and other structures is not available.
In computed tomography, the X-ray beam moves in a circle around the body.This allows many different views of the same organ or structure. The X-rayinformation is sent to a computer that interprets the X-ray data anddisplays it in a two-dimensional form on a monitor.
CT scans may be done with or without contrast. Contrast refers to asubstance taken by mouth or injected into an intravenous line thatcauses the particular organ or tissue under study to be seen more clearly.Contrast examinations may require you to fast for a certain period of timebefore the procedure. Your doctor will notify you of this prior to theprocedure.
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Potentiation Of Angiotensin Ii Effects Reduction Of No Bioavailability And Direct Constriction Of Medullary Descending Vasa Recta: Formation Of Reactive Oxygen Species
Sendeski et al47 demonstrated in vitro in isolated outer medullary descending vasa recta of rats microperfused with a solution of iodixanol that this contrast drug directly constricted these vessels by 52%, reduced NO, and increased the vasoconstrictor response to angiotensin II. The consequence of this constriction in vivo will be severe local hypoxia36 . The same authors demonstrated an important role for reactive oxygen species in constricting medullary vasa recta following contrast-drug administration in fact, the superoxide dismutase mimetic Tempol reduced the vasoconstriction by iodixanol.36,47
It is also known that in normal kidneys, epithelial tubular transport leads to ROS formation, particularly in the medullary thick ascending limb of Henles loop, where the dense mitochondrial population is the main source for the generation of superoxide anions , and hydroxyl radicals by NADH-oxidase.48,49 The injection of a contrast drug causes an increase in ROS formation and oxidative stress that exerts direct injury to endothelial and epithelial cell membranes in vascular and tubular structures, respectively, which leads to cellular apoptosis and necrosis and increased medullary hypoxia49 .
The Types Of Contrast Dye
|Need to drink about 1L-1.5L||Depends on the patients age and/or size|
|Used to enhance the images of internal organs like the heart, lungs, liver, adrenal glands, kidneys, pancreas, gallbladder, spleen, spleen, uterus, and bladder soft tissues of the body, brain, and breast||Used to enhance the images of the gastrointestinal tract||Used to enhance images in the colon, rectum, and large intestines|
Other types of contrast include gas and intrathecal contrast. Gas contrast is a type of contrast that patients inhale for a special lung and brain CT scan or a Xenon enhanced CT scan.
On the other hand, an intrathecal contrast is injected into a spinal sac which enhances the images of the spinal canal and nerves.
How Can I Reduce My Risk Of Kidney Problems Associated With Contrast Dyes
You can reduce the risk of CIN, NSF and other kidney problems associated with contrast dyes.
- Know your GFR, especially if you have chronic kidney disease or are at high risk for CKD
- Tell each member of your healthcare team about CKD, particularly if you need to undergo an MRI or CT
- If you need to have an MRI or CT, ask your doctor or radiologist about your risk factors
- Follow all instructions before, during and after the procedure
- Allow your body enough time to clear the contrast dyes before having more tests that use contrast
- Know the signs and symptoms of CIN and NSF
For more information about the use of MRI or CT contrast dyes and kidney problems, speak with your doctor or radiologist.
D Physical Examination Findings
Patients with radiocontrast dye-induced nephropathy are typically non-oliguric and thus there are no classic physical exam findings associated with this condition. However, a physical exam is important for ruling out other causes of acute kidney injury such as drug-induced interstitial nephritis , cholesterol emboli , volume depletion , or decompensated heart failure .
Acute Kidney Injury By Radiographic Contrast Media: Pathogenesis And Prevention
It is well known that iodinated radiographic contrast media may cause kidney dysfunction, particularly in patients with preexisting renal impairment associated with diabetes. This dysfunction, when severe, will cause acute renal failure . We may define contrast-induced Acute Kidney Injury as ARF occurring within 2472hrs after the intravascular injection of iodinated radiographic contrast media that cannot be attributed to other causes. The mechanisms underlying contrast media nephrotoxicity have not been fully elucidated and may be due to several factors, including renal ischaemia, particularly in the renal medulla, the formation of reactive oxygen species , reduction of nitric oxide production, and tubular epithelial and vascular endothelial injury. However, contrast-induced AKI can be prevented, but in order to do so, we need to know the risk factors. We have reviewed the risk factors for contrast-induced AKI and measures for its prevention, providing a long list of references enabling readers to deeply evaluate them both.
It is well known that using iodinated radiographic contrast media may cause kidney dysfunction, especially in patients with preexisting renal impairment and in those with diabetes. This dysfunction may range between a slight increase in serum creatinine and severe acute renal failure with anuria .
4. Risk for Development of AKI
Hereafter we discuss the different risk factors.
Does Contrast Dye Make You Tired
Asked by: Samanta Kohler
Gadolinium, a rare earth metal, is used to as a contrast agent to improve the quality of images in around 30% of MRI scans. But some patients claim they have experienced debilitating pain, chronic fatigue and involuntary muscle spasms after being injected with the chemical.
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Risk Of Bias In Individual Studies
The study quality and the presence of potential bias within individual studies will be done at both the outcome level and the study level. Two reviewers will complete the assessment independently. Randomized controlled trials will be evaluated using the Cochrane Risk of Bias 2.0 tool for individually randomized, parallel group trials . The Newcastle-Ottawa Scale will be used to evaluate observational studies . A table comprised of study characteristics will illustrate the results from this methodology quality assessment.
What Are Nephrogenic Systemic Fibrosis And Contrast
Nephrogenic systemic fibrosis This condition is rare and, so far, has occurred only in people with severe kidney disease including patients on dialysis. It causes swelling and tightening of the skin of the arms and legs, and less often the body. It develops over days to weeks after gadolinium contrast is given, and might reduce movement of the joints. In rare cases, it can also cause damage to internal organs.
Certain types of gadolinium contrast are now well known to be associated with a much lower risk of NSF in people with poor kidney function. If you need to have gadolinium contrast, the radiologist will use one of these lower risk types of gadolinium contrast. It is now thought that less than 1 in 100 people with severe kidney function impairment who have these lower-risk types of gadolinium contrast will develop NSF. It is often possible to carry out MRI without using any gadolinium contrast agents, and this is preferred where possible for patients with very poor kidney function or who are on dialysis.
Contrast-induced nephropathy If you already have very poor kidney function, but are not on permanent dialysis due to kidney failure, there is a small risk that iodinated contrast will make your kidney function temporarily worse . This occurs mainly in people who have large amounts of iodine-containing contrast medium given into an artery or if they have more than one CT scan using intravenous contrast in a short period of time that is, hours to 12 days.
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Contrast Dye In Kidney Disease Patients: Reducing The Risk Of An Important Diagnostic Tool
Building the evidence base for best practice
Medical research has resulted in many amazing diagnostic and treatment methods, tools and drugs. Today a physician can look inside her patients body through the aid of radiation and iodine-based dyes in the blood stream both of which could be deadly in another time or place. This same physician can then determine how well different organs are functioning and how clear blood vessels are.
However, this is not without risk. For example, in the case of patients with kidney disease, doctors need to use radioactive dyes to determine how well the kidneys are functioning. This information helps them decide what additional treatment is necessary. But the dyes themselves may cause damage to the kidneys referred to as contrast-induced nephropathy. Furthermore, without further investigation, it is not always evident which patients may be at high risk.
There are two main contrast dyes used for kidney disease patients today iohexol and iodixanol. Mayo Clinic health care delivery researchers in Florida sought to determine what the best available option was for patients. They reviewed available literature, and found that reported rates of contrast induced nephropathy ranged from 8 to 50 percent variability they found unacceptable when seeking evidence for best practice.
What Is The Evidence
Mueller, C, Buerkle, G, Buettner, H, Petersen, J, Perruchoud, AP, Eriksson, U, Marsch, S, Roskamm, H. âPrevention of contrast media-associated nephropathy: randomized comparison of 2 hydration regimens in 1620 patients undergoing coronary angioplastyâ. Archives of Internal Medicine. vol. 162. 2002. pp. 329-336.
Hoste, E, De Waele, J, Gevaert, S, Uchino, S, Kellum, J. âSodium bicarbonate for prevention of contrast-induced acute kidney injury: a systematic review and meta-analysisâ. Nephrology, Dialysis, Transplantation. vol. 25. 2010. pp. 747-758.
Lee, S, Kim, W, Kim, Y, Park, S, Park, D, Yun, S, Lee, J, Kang, S, Lee, C, Lee, J, Choi, S, Seong, I, Suh, J, Cho, Y, Lee, N, Cheong, S, Yoo, S, Lee, B, Lee, S, Hyon, M, Shin, W, Lee, S, Jang, J, Park, S. âPreventive strategies of renal insufficiency in patients with diabetes undergoing intervention or arteriography â. American Journal of Cardiology. vol. 107. 2011. pp. 1447-1452.
Solomon, R, Gordon, P, Manoukian, S, Abbott, J, Kereiakes, D, Jeremias, A, Kim, M, Dauerman, H. âRandomized trial of bicarbonate or saline study for the prevention of contrast-induced nephropathy in patients with CKDâ. Clinical Journal of the American Society of Nephrology. vol. 10. 2015. pp. 1519-1524.
Tepel, M, van der Giet, M, Schwarzfeld, C, Liermann, D. âPrevention of radiographic-contrast-agent-induced reductions in renal function by acetylcysteineâ. New England Journal of Medicine. vol. 343. 2000. pp. 180-184.
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